Window construction designs for a passenger vehicle such as a bus or railroad passenger car can provide means of exiting the vehicles with minimum effort and minimum loss of time. Typically such windows include a framed panel hinged to the wall of the vehicle, and a latch assembly. The window can be quickly unlocked or disengaged and allowed to pivot outward, allowing a passenger to leave the vehicle by way of the window. These latching window assembly designs must meet stringent test specifications to hold the window in place under substantial loading, they must provide a watertight seal, and they must minimize vibrational noise.
Various latch mechanisms are known in the prior art. For example, U.S. Pat. No. 3,942,286 teaches the use of a latch assembly comprising a release bar hingedly mounted to the frame of a window. The release bar has a contoured socket. A keeper bar is formed with an elongate bead of cylindrical configuration. The release bar is snap fitted over the keeper. Lifting the release bar allows the window to be opened.
A problem arose during assembly of the latch mechanism to the vehicle. Because of the improper initial settings during assembly, the keeper mechanism would not always fit snugly to the release bar. To compensate for this U.S. Pat. No. 4,313,280, assigned to the assignee of the instant application, allowed adjustment of the keeper with a pair of set screws.
Another known window assembly design teaches the use of a keeper mounted to a wall, a release bar with a show surface mounted to a lower frame of the window assembly and a release bar retention block to hold the release bar in an up position, keeping the release bar from contacting the wall and possibly damaging the show surface of the release bar when the window is pivoted.
A problem with these designs is that the latch assembly is dependent on a tight fit between the release bar and a keeper mechanism. If the lower frame assembly becomes damaged, dented or crushed due to an impact, or if the parts are not dimensioned or produced accurately, the keeper may not fully engage the release bar resulting in rattling, and an imperfect seal.
It is an object of the present invention to provide a window with an improved latch assembly having enhanced latch strength.
It is another object of at least certain preferred embodiments of the present invention to provide an improved release bar retention means, to prevent scuffing or scratching of the interior or show surface of the release bar.
It is another object of at least certain preferred embodiments of the present invention to provide a window assembly with an improved latch assembly such that the window can be closed and a latch member engaged without returning the release bar to its full down position.
Additional objectives will become apparent from the following disclosure.